Amazon and Salesforce are odds-on to join the UK government's G-Cloud and start serving civil servants with hosted computing, storage and ERP from May, reports the The Register.

The companies have been in talks to join G-Cloud, with government officials driving the programme having to reassure the firms' legal people on their obligations under the G-Cloud's terms and conditions.

The duo had passed on G-Cloud 1.0 which launched in February, over concerns about their legal obligations and responsibilities on things such as data audits.

Newly named G-Cloud leader Denise McDonagh revealed the development during a UKAuthority.com webcast on Thursday in response to The Register. McDonagh, who is also head of IT at the Home Office, was named on Friday as the successor to incumbent Chris Chant, who is retiring from the civil service after just 18 months in charge of G-Cloud.

Asked whether Amazon and Salesforce will be on the next version of G-Cloud, which currently gives hefty representation to existing suppliers of government IT like Microsoft, IBM and BT who have followed these two into cloud, McDonagh stopped short of saying she'd be disappointed if they didn't sign up, but continued: "I fully expect them to be on G-Cloud 2."

Commenting on the reason they hadn't joined up in February, she said: "There were some challenges. There was some language that gave their legal people a headache on the right to audit data. Since then we have spoken to the people at Amazon and Salesforce to explain the practicalities...therefore they are much more at ease with what we are asking them to do."

Amazon and Salesforce are synonymous with cloud computing. Amazon EC2 and S3 deliver hosted compute and storage at cut-throat prices while its APIs are soaking into business and consumer apps. Since spinning up in late 2006, Amazon has become the undisputed leader: with nearly 1tn data objects that sit in its silo and rapid expansion in the last 12 months. Everybody from OpenStack to Microsoft are racing to catch it.

Salesforce began in 1999 with a simple hosted customer relationship management (CRM) service. Through a combination of boisterous marketing by its chief executive Marc Benioff along with strategic development and acquisition, the company now counts among its offerings: a database-as-a-service; hosted websites; Amazon-style application hosting with Heroku; and crowd-sourcing and social networking apps for mobile and other devices which are used by Dell, Starbucks and others.

Both companies have created dedicated practices for the hosting of US government data and apps. The firms have managed this thanks to the fact that US government rules set a high bar on the physical location of servers hosting the nation's official data – and on who is allowed to come into contact with it.

The UK is less stringent, having an escalating level of rules based on sensitivity of the data and whether it falls under European data privacy rules or national law.

McDonagh reckoned the need to clarify the language of G-Cloud was among the lessons the government has learned building the next iteration of G-Cloud and Cloudstore. It had been necessary to simplify the wording and to reduce the number of acronyms to attract new suppliers and to explain the services, and to also cut the Ts and Cs from hundreds of pages to just 20.

Google - another tech name now synonymous with cloud - had no difficulty with the language of G-Cloud. As McDonagh pointed out, Google is already listed on the G-Cloud Cloudstore, right along with Microsoft and the others. Five of Google's products, APIs and services are listed including Apps for Business that features Gmail and calendar, Maps API Premier, and Chrome OS. Like so many vendors' services on G-Cloud, these are waiting to be "assured" while Google has not bothered to provide descriptions of what they actually are or do in all cases.

The government also plans more "buycamps" to explain G-Cloud and Cloudstore to its people and try to shift the culture of civil service IT procurement. Since February, McDonagh estimated that "20 to 30 things" had been sold though Cloudstore.

It was Salesforce's CEO Marc Benioff who last year berated the UK government for not going far enough on public cloud.

"The UK government is way behind in this, and way too much into virtualisation and the G-Cloud, which is basically just a big virtual machine that has not been executed well. Too much cost has gone into running too many data centres," Benioff is reported to have said in September, before G-Cloud floated.

In December, with a G-Cloud strategy document published and talk of an AppStore – which hasn't actually materialised – in the air, Benioff was patting the UK government on the head for coming around to his anti-VMware world view. The government's cloud was starting to gain "focus and momentum", he said.

The date for G-Cloud 2, meanwhile, might slip, McDonagh warned during the webcast. She noted while it's due at the beginning of May, she meant that "in a civil service" way.